“…Roerink et al (1) raise important and potential methodological biases that could have accounted for our finding regarding elevated TGF-β levels in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (2). Here, we provide additional information as requested by Roerink et al (1) that supports that the elevation of TGF-β in patients with ME/CFS is most likely to be rooted in the biology of ME/CFS and not due to methodological issues.…”